In: The EMBO Journal, 11 (1992), Nr. 4. pp. 1543-1551
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Abstract
The signal recognition particle (SRP) binds to signal sequences when they emerge from a translating ribosome and targets the complex of ribosome, nascent chain and SRP to the membrane of the rough endoplasmic reticulum (rER) allowing the co-translational translocation of the nascent chain. By photo-crosslinking it has been shown that the signal sequence of preprolactin(PPL) only interacts with the methionine-rich (NI) domain of the 54 kDa protein subunit (SRP54) of SRP. Here we show that (i) a signal-anchor sequence is likewise crosslinked only to the methionine-rich domain of SRP54,(ii) free SRP54 can interact with signal sequences independently of the other components of SRP, (iii) its M domain suffices to perform this function, and (iv) an essentially intact M domain is required for signal sequence recognition. Alkylation of the N+G domain in intact SRP54 with N-ethyl maleimide (NE), but not after cleavage with V8 protease, prevents the binding of a signal sequence to the M domain. This suggests a proximity between the N+G and M domains of SRP54 and raises the possibility that the role of the N+G domain may be to regulate the binding and/or the release of signal sequences.
Document type: | Article |
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Journal or Publication Title: | The EMBO Journal |
Volume: | 11 |
Number: | 4 |
Date Deposited: | 15 Jul 2008 17:26 |
Date: | 1992 |
Page Range: | pp. 1543-1551 |
Faculties / Institutes: | Service facilities > Center for Molecular Biology Heidelberg |
DDC-classification: | 570 Life sciences |
Uncontrolled Keywords: | GTP binding protein , methionine-rich domain of SRP54 , photo-crosslinking , signal sequence binding , signal recognition particle |
Series: | Works by Bernhard Dobberstein |